i noticed that alot of engine overhaul kits state that they will fit super a thru serial number 310xxx. did the c123 go in after that serial #? and does that make it a super a-1. and can somebody shed some light on the A V and A V-1. thanks

He that tilleth his land shall be satisfied with bread: Proverbs 12:11

When the Super C replaced the C, the engine was changed from 113 ci to 123 ci. With this change, the lower bore of the engine block was increased and the lower ends of the sleeves (wet sleeve engine) were enlarged along with the increased bore. From this time forward, the Super A used the Super C block with the larger lower bore. The Super A sleeve was resized to fit the larger lower bore but the original 3" piston bore was retained. Thus the later Super A has the same displacement as the earlier Super A, but the different OD of the sleeves requires a different sleeve and piston kit.

The tractor commonly refered to as a Super A1 had several changes from the Super A, including most of the things that changed from a C to a Super C. The Super A1 had the larger 3-1/8" bore, raising the displacement to 123ci. It also had a water pump and taller radiator. The taller radiator required different sheet metal and a raised gas tank, like the Super C. One thing that did NOT change was the decals. The hood of a Super A1 simply said "Super A". By the way, IH internal documents often differentiate the Super A from the Super A1 as Series 1 and Series 2.

I'm not sure what your AV question is. The "V" designation identifies the high clearance variant of the tractors. Whether you are looking at an A, Super A or Super A1, the changes to make a high clearance tractor were about the same.

While I'm at it, I might as well head off the question of the AI (letter I, not number 1). There were industrial/commercial versions of these tractors. There were a few modifications made for these versions. These were properly called "International A" or "International Super A". Labeling on the tractors was changed accordingly. Anything on the tractor that said "Farmall" was replaced with "International". The word "culti-vision" was removed. The model ID on the side of the hood was either "A" or "Super A". They did NOT use a designation "AI". You see a lot of them at shows. They are all inaccurate replacement decals.